Carlo Grassi (1520 – 25 March 1571) was an Italian Roman Catholic bishop and cardinal.
[1] During the sede vacante of 1559, the College of Cardinals appointed him to be governor of Rome, a post he held from 19 August 1559 until 26 March 1560.
[1] On 30 March 1560 Pope Pius IV named him governor of Umbria and Perugia, with the title of vice-legate from 5 May 1560 until June 1561.
[1] He participated in the Council of Trent from 11 November 1562 until its closing in 1563; he was named a member of the commission to revise the decree of reform on 8 October 1563.
[1] The pope charged him with seeking the support of the Republic of Venice and Spain for war against the Ottoman Empire.